Percentage Change Calculator
Find the percentage change between two numbers, or plot the point-to-point percentage change across a whole series of values.
All calculations run in your browser. Nothing is sent to a server.
Comparing two numbers is a one-step calculation covered by the Percentage Calculator and the Percentage Increase/Decrease Calculator, but tracking something over time (weight, expenses, a stock price, website traffic) means looking at a whole series of point-to-point changes, not just a start and end value. The second mode below plots that whole series at once, showing where the real movement happened rather than just the net result.
Related Calculators
How It Works
A budget going from $1,200 to $1,400 across a series of months isn't one change, it's several: month to month, the percentage change can go up, down, or flatten out, and looking only at the first and last number hides that pattern entirely.
Real Situations Where This Applies
Tracking monthly expenses, a weight-loss or fitness log, a small business's weekly revenue, or a stock price over several trading days all involve a series of numbers where the point-to-point percentage change tells a more useful story than a single start-to-end comparison. A number that ends up flat overall can still have swung wildly in between, and a series view catches that.
Personal Finance Tracking
A monthly spending log that ends the year at roughly the same total it started with can still have included a month where spending spiked 40% above average, followed by a month of cutting back. Looking only at January versus December hides that spike entirely, while a series view of every month makes it visible and easier to explain.
Business and Sales Reporting
Weekly or monthly revenue figures are usually more useful compared point to point than as a single year-over-year number, since a business can have a strong overall year while still experiencing a rough quarter in the middle that's worth investigating. If a single quarter's swing turns out to trace back to a specific pricing decision, the Markup Calculator can help check whether a margin change played a role. Reporting only the annual change can mask exactly the kind of dip a manager would want to catch early.
Health and Fitness Logs
A weight or fitness measurement tracked weekly rarely moves in a straight line. Plotting the percentage change between each entry (rather than just the first and most recent) shows the actual pattern of progress, including plateaus or temporary reversals, which a single overall percentage would flatten into one misleading number.
Common Mistakes
Frequently Asked Questions
What's the difference between this and the Percentage Increase/Decrease Calculator?
That tool is built for a single change or a sequence of manually entered changes. This one is built for comparing two values directly, or plotting the change across an entire series of numbers at once.
Why does a flat overall change sometimes hide big swings?
Because comparing only the first and last value in a series ignores everything that happened in between. A value that goes up sharply and then back down can end at the same place it started while still having a volatile history.
Can I use this for tracking my weight or expenses over time?
Yes. Enter each data point in order in the "Track a Series" mode, and it shows the percentage change from each point to the next.
How many data points can I enter in the series mode?
As many as you have, separated by commas. The tool calculates the point-to-point change between every consecutive pair automatically.
What does a red bar in the trend chart mean?
Red bars mark a decrease from the previous point, and teal bars mark an increase. Scanning the colors quickly shows the overall pattern of a series before reading the individual percentages.